Stockholders' Equity - Additional Information (Detail)		1 Months Ended		3 Months Ended		6 Months Ended		12 Months Ended
	May. 10, 2013 USD ($) $ / shares shares	Jan. 31, 2015 shares	Jun. 30, 2014 USD ($) shares	Jun. 30, 2015 USD ($) $ / shares shares	Jun. 30, 2014 USD ($)	Jun. 30, 2015 USD ($) $ / shares shares	Jun. 30, 2014 USD ($) shares	Dec. 31, 2014 USD ($) $ / shares shares
Class Of Stock [Line Items]
Preferred stock, shares issued				0		0		0
Preferred stock, par value | $ / shares				$ 0.001		$ 0.001		$ 0.001
Preferred stock, shares outstanding				0		0		0
Compensation expense | $				$ 9,381,000	$ 7,044,000	$ 16,058,000	$ 7,241,000
Number of shares authorized for grant under equity incentive plan				2,201,772		2,201,772
Employee Stock
Class Of Stock [Line Items]
Compensation expense | $						$ 200,000
Number of shares authorized for grant under equity incentive plan				360,000		360,000
Employee Stock | Evergreen Provision
Class Of Stock [Line Items]
Number of shares authorized for grant under equity incentive plan		800,354
Maximum percentage of capital stock						1.00%
Issuance of additional authorized share		440,354
Number of shares issued under ESPP						23,655
Employee Stock | Evergreen Provision | Maximum
Class Of Stock [Line Items]
Issuance of additional authorized share						720,000
Employee Stock | Evergreen Provision | Minimum
Class Of Stock [Line Items]
Issuance of additional authorized share						0
Series A Convertible Preferred Stock
Class Of Stock [Line Items]
Preferred stock, shares issued	20,315,397
Conversion of convertible securities into preferred stock, Shares							20,315,397
Conversion ratio of preferred stock into common stock			1
Payment of preferred stock dividend in common stock, shares			78,509
Payment of preferred stock dividend in common stock, value | $			$ 2,524,894
Series A Preferred Stock
Class Of Stock [Line Items]
Preferred stock, shares issued	10,792,725
Preferred stock, par value | $ / shares	$ 1.8531
Gross proceeds from issuance of preferred shares | $	$ 19,999,999
Issuance costs of preferred shares | $	$ 148,741
Convertible promissory note, Interest rate	4.00%
Debt instrument, Accrued interest | $	$ 254,411
Conversion of convertible securities into preferred stock | $	$ 14,995,525
Conversion of convertible securities into preferred stock, Shares	9,522,672
Per share price of series A Preferred Stock issued during debt conversion | $ / shares	$ 1.5751
Discount to the purchase price, percentage	15.00%
Warrants issued for purchase of aggregate shares	159,049
Preferred shares received	148,146
Outstanding warrants | $	$ 122,500
Preferred Stock, Voting Rights						1
Preferred stock, dividend rate, percentage						6.00%
Dividends, preferred stock, cash | $								$ 1,435,723
Series A Preferred Stock | Minimum Shares To Maintain Holders Rights
Class Of Stock [Line Items]
Preferred stock, shares outstanding				2,000,000		2,000,000